Video format developed to allow the storage and transmission of digital video. The 625/50 SIF format has a resolution of 352 x 288 active pixels and a refresh rate of 25 frames per second. The 525/59.94 SIF format has a resolution of 352 x 240 active pixels and a refresh rate of 29.97 frames per second. MPEG-1 allows resolutions up to 4095 x 4095 active pixels, however, there is a “constrained subset” of parameters defined as SIF. The computer industry, which uses square pixels, has defined SIF to be 320 x 240 active pixels, with a refresh rate of whatever the computer is capable of supporting.